1. Field of the Invention
The present invention relates to image forming apparatus, and particularly to maintenance work support apparatus for maintenance work by servicemen for image forming apparatus of electrophotographic system capable of communication with external devices.
2. Description of the Related Art
The electrophotographic process includes a charging process for uniformly charging a surface of a photoreceptor, an exposure process for exposing the surface of the photoreceptor according to image information to partly remove charge in order to form a latent image, a developing process for sticking toner in a developing device to the latent image to form a toner image, a transfer process for transferring the toner image to record paper (hereinafter, referred to as "paper"), and a fixing process for fixing the toner image transferred to the paper, which is widely used as a method of forming a hard copy image.
Image forming apparatus employing the electrophotographic process include a copying machine, a facsimile, and optical printers employing a laser or an LED array as light sources. These image forming apparatus usually have a CPU (Central Processing Unit) including a microprocessor and so forth, in which each portion is controlled according to a control program.
Now, conventionally, as described in Japanese Patent Laying Open No. 59-142559, for example, control systems in which each copying machine and a control unit (host) are connected to each other through a communication line in order to concentrically control a plurality of copying machines have been known.
A copying machine configuring such a control system has means for storing data corresponding to control items, in which the data is transmitted to the host according to a command from the host.
The conventional control items are mainly for grasping operational (use) conditions of the copying machines, such as the number of copies for each user and the sizes of employed paper.
That is, a conventional control system is made for an object of rational use of each copying machine, that is, enabling easy totalization of data for implementing payment of maintaining cost by beneficiaries, equality of used amount for each user and so forth, at a user side having a plurality of copying machines such as public agencies and companies.
Recently, a development of a maintenance control system is in progress in which a host provided at a service base (a service station) where servicemen are waiting and each of a plurality of image forming apparatus provided at each user are connected to each other in an on-line manner in order to implement efficient maintenance for image forming apparatus.
In the present specification, maintenance means the whole activity for maintaining operational conditions (hereinafter, referred to as "condition") of image forming apparatus normal, which includes work by servicemen at users such as periodical checking and repair of troubles (fails and bad conditions) and activities for supporting the field work, that is, activities of totalization and analysis of conditions of trouble occurrence and improvements in an operation manual and so forth.
In a maintenance control system, the control items mainly relate to conditions of image forming apparatus. The image forming apparatus is provided with a function of transmitting to a host condition data corresponding to the conditions indicated by output signals of sensors in respective parts and so forth.
By controlling conditions of each image forming apparatus at a service station, if a trouble occurs, a serviceman estimates the contents of the trouble with the condition data and visits a user with prepared necessary repairing parts, which enhances efficiency of maintenance.
In controlling the conditions, the condition data preferably shows the conditions in more detail. That is, a sensor for detecting element values of each portion in detail is preferably provided in an image forming apparatus.
Actually, however, because of some reasons such as limitation of space and cost and lack of suitable sensor means, the number of sensors and spaces for arrangement thereof are limited in an image forming apparatus, so that the contents of conditions shown by condition data have a limitation.
Accordingly, in the field work for periodical checking or trouble occurrence, a serviceman synthesizes the conditions indicated by condition data and conditions detected by the sense of the serviceman himself, selects a preventive measure or a counter measure for the trouble on the basis of the information and his own knowledge, and does his work for cleaning, parts replacement, alteration of set values and so forth in accordance with the selection.
Conventionally, however, there has been a problem that the work required a long time because, for example, it was difficult to find out a cause of a trouble, or the procedure of the measure was complicated due to fail occurrence in many portions. Especially, a serviceman having less knowledge based on experience has a difficulty in the work.
Also, a mistake might occur in finding out a cause of a trouble or in the procedure of work, which might facilitates some fails on the contrary.
On the other hand, condition data from each image forming apparatus collected and accumulated at a service station can be utilized as so-called field information (market information) in the aspect of maintenance in view of the maker side (seller side).
For example, the occurrence of troubles can be reduced by totalizing conditions of trouble occurrence on the basis of the condition data to perform periodical checking focusing on portions related to troubles with high occurrence frequency.
In accumulating such field information, the condition data preferably show conditions in more detail as is the case of the above-described condition control. That is to say, in an image forming apparatus, sensors sensing condition in each portion all over the apparatus are preferably provided.
The number of sensors and spaces for provision thereof in an image forming apparatus, however, have a limitation as described above.
Accordingly, conventionally, in maintenance control of image forming apparatus, it has been difficult to accumulate detailed information related to conditions.